Modern endoscopes, primarily if they comprise a video camera or are coupled to a video camera, are able to supply high-quality two-dimensional images from within a patient's body or from a cavity in a machine. However, a three-dimensional visual impression or a three-dimensional image is desirable for many applications. A three-dimensional image can enable a more accurate assessment of distances, lengths, areas, convex and concave curvatures and volumes and thus also support a more reliable diagnosis or a rapid, economic, safe and atraumatic intervention.
A stereoscopic endoscope, in which two images acquired from spaced-apart points are transmitted separately to the proximal end, in view of the required structural space and the tendency toward ever smaller shank cross sections, can be realized at best with extreme complexity and with other disadvantages being accepted. Therefore, a series of approaches exist for acquiring a high-quality two-dimensional image and in addition the distances between the observed surfaces and the distal end of the endoscope. Using the two-dimensional image and the distances, it is possible to calculate a stereoscopic image (with a respective partial image for the left eye and for the right eye of the observer) which imparts a three-dimensional impression to the observer. It is particularly advantageous that for this purpose, under certain circumstances, a conventional or only slightly modified endoscope can be used and a modification is necessary only on the camera device.
DE 10 2006 017 003 A1 (Jochen Penne, F A U Erlangen) describes an endoscope for depth data acquisition. A light source 102 emits infrared light modulated in accordance with modulation information (paragraphs [0046], [0051]). A photon mixing detector 108 receives light and generates a sensor signal representing the received light. The sensor signal is evaluated using the modulation information on the basis of the “time-of-flight” principle in order to calculate depth data from the time of flight of the received light signal (paragraphs [0018], [0030], [0042], [0047], [0048], [0049]). Besides a matrix of depth data or distance values, it is possible to generate a matrix of intensity information or intensity values from the sensor signal (paragraph [0018]). A further light source 202 for generating a daylight spectrum and a further sensor 302 can be provided for obtaining image data (paragraphs [0023], [0054], [0062]). Alternatively, the light source generates light in the visible spectrum range and an observer perceives the scene in this light (paragraph [0060]).
DE 10 2007 006 351 A1 (Frederic Sarrat, Logitech) describes an image acquisition. Light is split by means of a splitter and guided partly to a first sensor for acquiring information in two dimensions and partly to a second sensor for acquiring information in a third dimension (paragraphs [0011], [0012], [0036], [0040], [0041], [0046]). Furthermore, sensors are described which comprise, besides pixels for red (R), green (G) and blue light (B), infrared-sensitive pixels (D) for distance measurement (FIGS. 3A, 3B, 3C, paragraphs [0034], [0035]).
DE 10 2008 018 636 A1 (Beat Krattiger, Karl Storz) describes an endoscopic 3D data acquisition. By means of a beam splitter, radiation returning from an object is imaged onto one of a plurality of image sensors (paragraph [0018]). One sensor is phase-sensitive. If image sensors having different sensor sizes are used, a matching optical unit is arranged between the beam splitter and at least one image sensor (paragraph [0023]). A stereoscopic image is synthesized from a 2D image of the observed region and distance information (paragraphs [0036], [0037]).
DE 10 2008 018 637 A1 (Beat Krattiger, Karl Storz) describes a fluorescence imaging with a (temporally) modulated fluorescence excitation radiation (paragraphs [0011], [0012]). Fluorescence radiation is imaged onto a phase-sensitively drivable solid-state sensor (paragraphs [0019], [0020]). By means of a beam splitter, radiation received (from the illuminated object) is guided onto further sensors (paragraphs [0031], [0032], [0033]). In the case of sensors of different formats, a matching optical unit is provided (paragraph [0035]).